Create mechanisms to easily extend the kinds of number types FloatTracker supports

[ashton314]

I'm adding support for complex numbers right now: it would be interesting if we could make this sort of thing easy for consumers of FloatTracker to do.

[bennn]

Ingredients for a new type:

• [ ] write cast function to/from TrackedX
• [ ] identify the error values for that type
• [ ] collect list of operations to override
• [ ] override each operation, add logging